Price Elasticity of Demand Equation Calculator

Measure demand sensitivity from price and quantity movements. Use midpoint or standard percentage calculations easily. Review exports, examples, formulas, and decision-ready interpretation below today.

About This Calculator

This calculator helps analysts measure how strongly quantity demanded responds to a price change. It supports both the standard percentage method and the midpoint method, so you can compare sensitivity under different reporting rules.

It also summarizes revenue movement, labels the result as elastic, inelastic, or unitary, and plots the change between two price-quantity points. That makes it useful for pricing reviews, dashboard checks, and quick business analysis.

Calculator Input Form

Example Data Table

Method Original Quantity New Quantity Original Price New Price PED Classification
Midpoint 100 120 10 9 -1.7273 Elastic
Midpoint 150 140 20 21 -1.4138 Elastic
Standard 80 76 15 16 -0.7500 Inelastic
Standard 300 330 12 11 -1.2000 Elastic

Formula Used

Standard formula: Price Elasticity of Demand = (% Change in Quantity Demanded) / (% Change in Price)

Standard percentage change in quantity: ((Q2 - Q1) / Q1) × 100

Standard percentage change in price: ((P2 - P1) / P1) × 100

Midpoint formula: [((Q2 - Q1) / ((Q1 + Q2) / 2)) × 100] / [((P2 - P1) / ((P1 + P2) / 2)) × 100]

Interpretation rule: If absolute PED is greater than 1, demand is elastic. If it is less than 1, demand is inelastic. If it equals 1, demand is unitary elastic.

How to Use This Calculator

  1. Enter the original quantity demanded.
  2. Enter the new quantity demanded after the price change.
  3. Enter the original price and the new price.
  4. Select either the midpoint method or the standard percentage method.
  5. Choose the number of decimal places you want.
  6. Click the calculate button to show the result above the form.
  7. Review the elasticity, classification, revenue effect, and graph.
  8. Download the result as CSV or PDF when needed.

Frequently Asked Questions

1. What does price elasticity of demand measure?

It measures how much quantity demanded changes when price changes. The coefficient helps analysts estimate customer sensitivity and predict sales response under different pricing conditions.

2. Why is demand elasticity often negative?

Demand usually moves opposite to price. When price rises, quantity demanded often falls. That inverse relationship makes the signed elasticity coefficient negative in ordinary market behavior.

3. What is the difference between midpoint and standard methods?

The standard method uses the starting value as the base. The midpoint method uses the average of old and new values, which reduces directional bias between two observations.

4. What does an elastic result mean?

An elastic result means quantity demanded reacts more than proportionally to the price change. In absolute terms, the coefficient is greater than one.

5. What does an inelastic result mean?

An inelastic result means demand reacts less than proportionally to the price change. In absolute terms, the coefficient is below one.

6. Why does the calculator show absolute elasticity too?

The signed result shows direction, while the absolute value supports classification. Businesses commonly use the absolute value to label demand as elastic, inelastic, or unitary.

7. Can this calculator help with revenue analysis?

Yes. It compares initial revenue with new revenue using price multiplied by quantity. That helps you quickly see whether the observed movement raised or reduced total revenue.

8. When should I prefer the midpoint method?

Use it when you want a balanced comparison between two points. It is especially helpful when you need a more stable estimate for reporting or teaching.

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.